Ukraine crisis: Pro-Russians seize Donetsk prosecutor's office
Hundreds of pro-Russian militants have seized the regional prosecutor's office in Donetsk, eastern Ukraine.
The attackers threw rocks at police before storming the building and raising the flag of the self-proclaimed Donetsk People's Republic.
Militants disarmed the police and ejected them from the building. There are reports of injuries on both sides.
Ukraine blames Russia for organising the seizures of a number of offices in the east. Moscow denies the claim.
Also in the Donetsk region, separatists seized the town council of Amvrosiyivka, local media reported.
In a separate development, German Chancellor Angela Merkel asked Russia in a phone call to President Vladimir Putin to help free foreign monitors held in eastern Ukraine.
The military observers were seized by pro-Russia separatists at a checkpoint in the flashpoint town of Sloviansk last Friday.
On Wednesday, a Russian military attache was detained in Ukraine on suspicion of spying and ordered to leave the country.
In Donetsk, the pro-Russian militants attacked the prosecutor's office, accusing those inside of siding with the government in Kiev.
The crowd later forced its way into the building, stripping weapons and shields from the police officers.
Many attackers chanted "Fascists! Fascists!".
One policeman running away from the prosecutor's office told the BBC's Steve Rosenberg: "How on earth can we deal with this kind of thing?"
Donetsk, an industrial hub of more than one million people, has seen a number of government offices seized in recent weeks.
On Wednesday, Ukraine's acting President Olexander Turchynov admitted that his forces were "helpless" to quell the unrest in some parts of the east, saying the goal was now to prevent it from spreading.
Mr Turchynov also said Ukraine was on "full combat alert", amid fears that Russian troops could invade.
Some 40,000 Russian troops are stationed close to the Ukrainian border. Moscow has warned that its soldiers will act if Russian interests in eastern Ukraine - where a majority of the population are Russian-speaking - are threatened.
Earlier on Thursday, Mr Putin reiterated his call for Kiev to withdraw troops from the south-east to open the way for a national dialogue.
The comments were made in the phone call with Mrs Merkel, the Kremlin said.
The US and EU have accused Russia of failing to implement the terms of last month's deal agreed in Geneva aimed at defusing the crisis by disarming illegal militias.
They have both stepped up sanctions against Russia this week, naming more individuals and companies facing travel bans and asset freezes.